A test instrument and method for operating the same are disclosed. The data acquisition system within the instrument generates signals and couples the signals to a device and/or receives signals from the device. The data processor within the instrument includes measurement specific software that generates measurements from the received signals, a restricted software application that utilizes the measurement data, and a physics API that interfaces the measurement specific software with the data acquisition system. The physics API provides a plurality of internal physics functions that are used by the measurement specific software to access the measurement data. The instrument includes an external API that maps the physics functions to an external set of physics functions that are available to the restricted software application and that hide the internal physics functions from the restricted software while providing access to a portion of the measurement data.